By Jonny Lupsha, Wondrium Staff Writer
An uptick in hurricanes is rendering their Greek naming system obsolete. In recent years, hurricane season has brought more storms with it, many of which arrive earlier than usual. Hurricane season is a complex system in meteorology.
The frequency of hurricanes is tied directly to the surface temperature of the ocean. As the Atlantic Ocean has experienced warmer waters for longer periods of time in recent years, hurricanes have formed more often and over a longer period of the calendar year. In fact, so many of these deadly storms struck in 2020 that meteorologists have chosen to drop the usual hurricane naming system which labels each one with a letter from the Greek alphabet.
Hurricanes are tropical cyclones that achieve sustained winds of more than 74 miles per hour. In his video series The Science of Extreme Weather, Professor Eric Snodgrass, Director of Undergraduate Studies for the Department of Atmospheric Sciences at the University of Illinois Urbana–Champaign, explained how hurricane season works.
The Longest Season
“The start of the hurricane season in the Atlantic Ocean is June 1,” Professor Snodgrass said. “On this date, we typically find, for the first time of the year, a large enough area of warm sea surface temperatures to support tropical cyclones’ formation. The very earliest date for a hurricane to form was June 8, when Hurricane Alma started the season in 1966 with the winds of 125 miles per hour.”
According to Professor Snodgrass, the number of hurricanes climbs significantly as August approaches, peaking around September 10. After this, the numbers decline until the end of hurricane season, which is at the beginning of December. Why does it peak when it does?
“Since hurricane strength and timing are directly tied to sea surface temperature, the peak of the season corresponds to a time of year when the Atlantic Ocean has its largest extent of warm surface water,” he said.
“Even though summer heat is greatest in June and July, the fact that water takes a longer amount of time to heat up compared to land delays the peak in the season by the surface temperatures by about six weeks.”
Where Hurricanes Make Landfall
It’s exceedingly rare for any kind of tropical cyclones to make landfall on the West Coast of the United States. Occasionally, remnants of hurricanes in the Pacific Ocean can push over onto the southwestern states, but otherwise, the West Coast is hurricane-free.
“By contrast, the Gulf Coast and the East Coast experience landfalling tropical cyclones that pose a threat to life and property from Texas to Florida to Maine every year,” Professor Snodgrass said. “The most vulnerable spots in the United States [are] the Mississippi Delta in Louisiana, the southern tip of Florida, and Cape Hatteras in North Carolina.
“These three regions jut out into the oncoming path of a typical hurricane track.”
According to Professor Snodgrass, since records have been kept, only three hurricanes have made landfall in the United States with Category 5 strength. Hurricane Andrew in 1992 was the most recent, affecting the south of Florida. It was preceded by Hurricane Camille in 1969, which made landfall along the Mississippi Gulf Coast near Waveland, Mississippi. And in 2005, Hurricane Katrina made landfall near Buras-Triumph, Louisiana. The earliest Category 5 hurricane on record to make landfall was the Labor Day hurricane of 1935, which struck the Florida Keys.
However they’re named, tropical cyclones shouldn’t be taken lightly. Causing tens of billions of dollars in damage and taking thousands of lives, they’re one kind of extreme weather for which those at risk should prepare.